Hey All,
It looks like many of you are upgrading to VB4 so this might not be of interest. For those still on older versions, I've gotten this up & running successfully using MW 1.16.0.
Additionally, I found that there is an incompatibility between this vb plugin and the mediawiki 'Lockdown' plugin (to restrict access to mediawiki namespaces by group and more -
http://www.mediawiki.org/wiki/Extension:Lockdown). This caused Lockdown to incorrectly remove usergroups from integrated members.
I also noticed (correct me if I'm wrong), that this plugin DOES NOT remove groups from users if they lose privileges in vbulletin. eg. if I am a bureaucrat today but tomorrow get removed from the vbulletin group which is supposed to give me that mediawiki group - I never get removed until it happens manually in Mediawiki.
I've fixed these two issues. I'll PM the mod owner to see if he wants to incorporate my changes (but I'm understand I'm pretty late in the game

)